並前往https://math.ymhs.tyc.edu.tw/masterchen/chenjt99/ScrClass/1082/%E9%AB%98%E4%B8%89/%E9%AB%98%E4%B8%89%E9%81%B8%E4%BF%AE%E4%B9%99%E4%B8%8A/%E7%BF%92%E4%BD%9C/Ch1.5%E6%8A%BD%E6%A8%A3%E8%88%87%E7%B5%B1%E8%A8%88%E6%8E%A8%E8%AB%96.pdf